Possible role of 3He impurities in solid 4He

We use a quantum lattice gas model to describe essential aspects of the motion of 4 He atoms and of 3 He impurities in solid 4 He. This study suggests that 3 He impurities bind to defects and promote 4 He atoms to interstitial sites which can turn the bosonic quantum disordered crystal into a metastable supersolid. It is suggested that defects and interstitial atoms are produced during the solid 4 He nucleation process where the role of 3 He impurities ( in addition to the cooling rate) is known to be important even at very small ( 1 ppm) impurity concentration. It is also proposed that such defects can form a glass phase during the 4 He solid growth by rapid cooling. Copyright (C) EPLA, 2007.